Pros
I've worked here nearly 20 years after stints in other industries with other employers. What really works here is the focus on staff development - this is not altruistic; consultants are worth more when they can do more, so you are encouraged & given opportunity to do more. Very strong focus on the relationship between the you and your Line Manager, who plays a mentoring role. Projects are varied across multiple scientific domains - common factor is they tend to be hard. Your colleagues are all smart people (high proportion of STEM PhD) and that makes for interesting office banter. You won't find people discussing Love Island in the break room. Hard work culture, not a long hours culture - what matters is getting stuff done, and done well. Very supportive of EU staff facing uncertainty over Brexit.
Cons
Can give impression of being more bureaucratic than a smaller company would be, but that in part is driven by a blue chip client list. Actually, management is way more flexible and needs driven than the staff manual implies.